Horn issue, don't think clockspring..one works/other doesn't?!?

Hey there folks!
I've been restoring a 2013 Tundra that I bought wrecked. (you can see my other threads for some detail pics if you'd like).
I'm about 'finished'....so, now I'm dealing with the 'smaller stuff'. Took it out for a test drive the other day and the guy in front of me at a stop light was either sleeping or texting when the light turned green, so I gave him a courtesy 'honk'....and was totally embarrassed. It turns out my high-pitched horn is working, but the low-pitched horn is NOT working. (so I sounded like a Chihuahua bark instead of a 'big dog')
I finally got a chance to check it, and the horn on the driver side works, but the horn on the passenger side does not.. I tried to troubleshoot by switching the horns (I had picked up a new(used) horn from a Tundra being parted out since one of my horns was physically damaged (small crack in plastic). When I switched the passenger horn to the driver side connection, it worked there too. So, I'm confused. Because of the accident, I switched out the steering wheel/airbag and clockspring from the parts truck.
I looked at the part numbers on the horns and they are different, so I'm assuming one is for high pitch and other pt no is for low-pitched, but don't know which is which. (see attached pic, one is 04040, other is 04020)
Any ideas on how to troubleshoot? I can't be heard in a Tundra sounding like a wimp
(I have tested the fuse and it is good, I see a relay for 'security horn', but figured that was unrelated)
your ideas are appreciated!
Thanks....George

DUH....just now saw in my picture the big H and big L....so I guess that answers my high/low question....but still not why one isn't working

 

Think about it… if one of them is working that means the switch fuse relays are all good.

With most of these circuits the switch fuse relay control one signal wire and then at the last step the signal is spilt off to two locations. One of you locations is good so your problem is from the split to the horn assembly itself somewhere.

If you moved the non working horn to the side of the working one and it now works then the horn assembly is good.

I would be looking at the pins in the connector of the side that doesn’t work. Trace the wires back, make sure one goes to ground and the other to the signal. You could pretty easily do this with a voltmeter on the continuity setting. (Assuming one of the wires is broken) Check for continuity on the ground of the working one to the ground of the non working one. Then do the same on the signal wire between the working one and the none working one. If one wire doesn’t have continuity that tells you they are not connected and there is a break somewhere.

Also make sure the pins in the connector look good and are not dirty or broken.

This is the wiring diagram from a 2014.

 

FYI it looks like the connection maybe one wire only meaning the signal wire is plugged into the horn and the horn is grounded to the truck via the bolt/mounting bracket. If this is the case you need a good clean mount to metal for a good ground.

You could also take the voltmeter and check fro voltage at the connector signal wire when the horn is pressed. One lead on the signal wire the other to ground. As someone hits the horn button you should get a voltage reading on the meter.

This would verify both signal wires are good and you have a ground issue.

 

Jeff_5_7,
Thanks...I appreciate your input!! One thing I noticed when troubleshooting, is that the horn that is NOT working only has 1 wire going to the connector(pass), the other side has 2 wires going to it(drver) (I assume by design). I definitely agree on the ground being established by the bolt. When I tested the horns outside the truck, I connected a clip to the inside of the connector(positive) and then just ran one from the metal on the horn assy. to the ground(using a 12v battery) and all horns are in 'working order'.
Now, I'm back to 'wondering" about the clockspring. I took the truck for a highway test drive and the cruise control wasn't working(properly). The dash lighted up "cruise control", but it would not set the speed. Its kinda like the horns..."parially working"
The reason I'm back to this is that I switched out the entire steering wheel when I exchanged the airbag, because I couldn't find an airbag for my steering wheel (without stereo controls)....So I swapped it all.
Think it could be somehow related to that???
thanks!!

 

The driver has two wires because one is the signal coming in from the steering wheel, the other wire is the signal going out to the passenger side horn. I would be check this wire as it seems the signal is not getting there to passenger side but the signal is making it into the driver side as it is working.

The truck will not set a cruise control speed if a trouble code is stored in the ECM. If the cruise light is coming on and off and the horn is working the clock spring is fine.

 

Jeff_5_7,
Thanks again! That makes sense. I'm sure I've got 'trouble codes' stored due to the accident. They aren't showing up on my Techstream, but I think that is a whole different problem. My airbag light is on, so I probably need to have the SRS controller reset to correct that. I'm guessing that could be the stored code that is preventing the cruise control too?? I don't have any other 'active codes' on the ECU per my Techstream check at least.

 

Check for 12v when you hit horn button. If it’s there… bad horn. And remember the horns ground through the mounting bolt to the chassis. The low horn I think feeds the high horn.

i bought some universal hella horns to replace mine when the same thing happened. They sounded ridiculous. Don’t go cheap I guess is the lesson.

 

Do you have the version of Techstream with the health check button? If so run that it scans every ecu for codes. A vehicle speed sensor code definitely renders Crusie unusable. Others might as well.

Can you even select and open the airbag control module in Techstream? Generally when they are locked full of crash data Techstream can even open/access the ecu.

Techstream is a very powerful tool that should be very beneficial to you in this process.

 

If Techstream is working properly you should be able to select and open say the engine ecu. Then click live data button. You will see data variables like RPM and all kinds of stuff update as the truck is running. You can also log select parameters

 

Jeff_5_7,
The info on the Health Check button was very helpful. I went to my truck to try it out and try to get some more understanding. I am going to post some pics of my results. Some I understand and some I don't have a clue.
pic 1: after hitting Health Check button, got this screen where I selected the top check mark (all ECU's)
pic 2: after running healthcheck, the results that came back. 3 DTCs (I elected to clear them)
pic 3: after re-running healthcheck after electing to clear DTCs (only Air conditioning remained - long story, but I know why that's there)
pic 4: ABS/VSC/TRAC screen showing C1333 - "open circuit in left rear speed sensor circuit" (which surely could explain issue with Cruise control, but why didn't it show up in Health Check???) - Just fyi too, I just replaced the rear ABS wiring harness because a tow truck operator damaged it and I had multiple lights on the dash (hi/low, etc), but after replacing harness and going for a drive, they are all gone now.
pic 5: Screenshot of my available systems on Techstream - Why are so many White with *(asterick) - ECU not supported or not responding???? And I posted this to answer your question about opening the SRS/Airbag ECU....I cannot open that ECU. Not sure it is my 'version' of Techstream (12.20) or something else

 

The C1333 left rear wheel speed sensor is on the health check. Check to make sure the sensor is plugged in since the harness has been replaced. This is most likely the reason your cruise isn’t working.

In my experience Techstream shows all ECUs available for that year you select however your truck might not have them all.

The airbag ecu should be responding unless it’s not because it’s full of crash data

 

Gotcha....I thought it weird though since even the TPMS ECU has the * and I KNOW my truck has TPMS ECU

 

Any wiring that was damaged in the crash? At least that you know of?

 

No damaged wiring that I have found/identified. I've checked each and every fuse (the battery was pushed back into the fuse box, so I was a little concerned about damaged wiring/electrical components there, but nothing has shown up)
I just a little while ago hooked my Techstream up to my son-in-law's 2008 Tundra and the same systems are showing as not available or not responding, so I am pretty sure now it is my 'version' of Techstream....very dissapointing...I'm going to have to try to get a new version of the software. I REALLY REALLY would like more functionality if not just to reset SRS ECU, then to at least be able to make a key or key fob for the truck.